Generally speaking, a vegetarian is a person who does not eat foods that consist of, or have been processed with animals. But within that category, there's a wide range of variety as to what a person who considers themselves a vegetarian will and will not eat. Here's the low-down:
A Lacto-Ovo vegetarian is the most common type of vegetarian. It is a person who doesn't eat meat or fish, but does eat both eggs and dairy products. These vegetarians get most of their protein from nuts, legumes, eggs, and dairy.
A Pescaterian is someone who does not eat meat, but does eat fish. This person also tends to follow suit with the rest of the Lacto-Ovo vegetarian diet too.
Lacto Vegetarians eat dairy products, but don't eat eggs. They eat everything that is eaten in a traditional vegetarian diet (Lacto-Ovo diet), except for eggs. Hence you can figure out that is why they are called Lacto vegetarians because lacto = dairy in latin.
The difference between Ovo vegetarians and traditional vegetarians is that they don't eat dairy, but they do eat eggs. Traditionally they try to only eat cage-free eggs because they are processed in the most humane way.
If being vegetarian isn't humane enough for you, you can ditch the eggs, honey, and dairy to become fully animal-free.Vegans are thought to live the healthiest lifestyles, but at the same time you have to give up so many great foods! I personally don't think I could do it, but it is the most humane and sustainable lifestyle out there.
Being a vegetarian is definitely hard, but because there are so many varieties it is definitely possible to conquer. It is worth trying at some point given the health and sustainability benefits. The Lacto-Ovo diet is definitely a possibility for me, but we will see if I can work my way to vegan.